Implanting magnets and RFID chips underneath the skin to experiment with is now relatively common, and while it’s risky to do these procedures without a doctor, they’re performed enough not to quite qualify as “extreme.” DIY ear magnets and night vision eyedrops, however, are pushing the limits of how people are hacking their bodies to enhance their capabilities.

Don’t get me wrong: The “grinder” community—people who do experimental biohacks on their own bods—are cool in my book. What was Jonas Salk, after all, but an old-timey grinder? Devices like pacemakers and cochlear implants are examples of valuable biohacks used by the medical community, and the biohacking movement is exploring cyborgism in ways that could lead to significant breakthroughs.

But most body hacks happen outside the medical community; they involve a DiY ethos by necessity. And some of the more risky biohacks steer away from daredevil self-improvement toward almost certain self-harm. For instance:

Night Vision Eyedrops

Image via Scienceforthemasses.org

Obviously night vision is cool. I would pay good money to see in The Night, both to stop stumbling over my sweatpants and to confront ghosts. So I get why this night vision biohack, in which grinder Gabriel Licina squirted Chlorin e6 (Ce6) into his eyeballs and wore black contacts to see in the dark, is appealing. And Licina reported that it worked temporarily, but it was a wholly subjective test.

Headphone Implants

Well-known grinder Rich Lee knew he was going blind, so he decided to implant magnets in his ears to enhance his ability to process sound. Lee took precautions, hiring a professional body modification artist, but it’s still a risky procedure, one that could lead to serious infection or amputation.

DIY Anticipatory Thermogenesis Training

When the body is cold, it amps up heat production. This process is called thermogenesis, and some biohackers are interested in it as a way to lose weight and become better acclimated to cold weather.

Exercise scientists have used ice baths to induce cold thermogenesis to prepare long-distance swimmers (like Louis Pugh, photographed above) for chilly water temperatures, but it’s a dangerous procedure to try at home, something grinder and Bulletproof coffee founder Dave Asprey found out first-hand when he left ice packs on his body too long and ended up burning himself.

“This is a real life situation where biohacking went wrong. It’s taken me weeks to recover and my last round of blood tests still show higher inflammation (C reactive protein or CRP) as a result,” he wrote.

A Huge-Ass Biometric Computer Chip

I’m not sure I need to tell you this was not done by a doctor, but it was not done by a doctor.

The idea behind this is a sane and fairly logical extension of the quantified self movement: An implantable tracker that measures your biometrics. The execution, however, leaves a lot to be desired, specifically a large chunk of of this dude’s arm. Getting more data about your health is never worth making your forearm look like it swallowed a VHS.

Header image via Scienceforthemasses.com

Nullification

A “nullo” is a cisgender male who elects to remove his genitals. Surgeries to complete this intense body modification have been done safely before, but amateur wannabe-eunuchs are still injuring themselves with DIY castration attempts.

This type of modification is a biohack in the sense that nullos are undergoing these processes to make their bodies better through removing unwanted parts. The nullo community is separate and very distinct from grinders, but is an extreme example of how body modification in the pursuit of an enhanced physique can mean very different things.